Hp 49g+ User Manual download pdf (Page 502)

Thus, the first three terms of the function are:

f(t) ≈ 1/3 – (4/π

)⋅cos (π⋅t)+(2/π)⋅sin (π⋅t).

A graphical comparison of the original function with the Fourier expansion

using these three terms shows that the fitting is acceptable for t < 1, or

thereabouts. But, then, again, we stipulated that T/2 = 1. Therefore, the

fitting is valid only between –1 < t < 1.

Function FOURIER

An alternative way to define a Fourier series is by using complex numbers as

Hp 49g+ User Manual Page 502